Quadra-circular window shade support base



FIG. 1 is a reduced perspective view of the quadra-circular window shade support base in use;

FIG. 2 is a perspective view of the quadra-circular window shade support base;

FIG. 3 is a left side view of the invention;

FIG. 4 is a top plan view of the invention;

FIG. 5 is a front elevation view of the invention;

FIG. 6 is a bottom plan view of the invention; and,

FIG. 7 is a right side view of the invention.

The broken lines in FIG. 1 are for purposes of illustration only and form no part of the claimed design. 

The ornamental design for a quadra-circular window shade support base, as shown and described. 